Valve arrangement for breathing devices



y 9, 1963 M. M. ARBORELIUS EI'AL 3,096,778

VALVE ARRANGEMENT FOR BREATHING DEVICES Filed Jan. 3, 1958 INVENTOR.

United States Patent 6 ('Jlaims priority, application Sweden Jan. 5, H572 Claims. (Cl. 137-63) The invention refers to breathing devices,particularly for operation. under water or. in smoke, of the type havinga membrane chamber with an inlet valve adapted to admit air from a.source of pressurized air in response to the membrane of the membranechamber and having an outlet valve and a breathing'aperture forconnection to a mouthpiece. The object of the invention is to provide avalve arrangement in devices of this type which makes possiblesubstantial saving of air, whereby the device can be used for a longertime than has hitherto been possible without renewal of the storedpressurized air.

It is. known to arrange the outlet valve in a valve cham ber separatefrom the. membrane chamber and also to arrange this valve on one of thewalls of the membrane chamber. Particularly for under Water work it isof advantage to place the outlet valve in the same plane as the membraneof the membrane chamber, since the outlet valve and the membrane arethen responsive to the same hydrostatic pressure. The disadvantage ofthe constructions in which the outlet valve is located in one of themembrane chamber Walls is that the chamber is filled during theexhalation with exhaled air. In the succeeding inhalation air, which isbad from a physiological viewpoint is returned to the wearers lungsbefore he receives fresh air from the membrane chamber. In addition, thefresh air remaining in the chamber after an inhalation is spilled duringthe exhalation.

The present invention removes these disadvantages, enabling the freshair remaining in the air passages of the wearer land of the device afteran inhalation to b retained in the system during the exhalation.

A few examples of the application of the invention is illustrated on thedrawing, FIGS. 1 and 2 of which show schematically each one embodimentin axial section and FIG. 3 of which shows a detail of the FIG. 2device.

In FIG. 1, a membrane chamber 1 is provided with an inlet valve 2 havingan inlet tube 3 for connection to a source of pressurized air. Anactuating member in the form of a two-armed lever 4 is actuated by acormgatted membrane 6 forming the upper wall of the chamber, in such away that the valve 2 is opened upon deflection of the membrane inwardly,such as during an inhalation. The chamber is provided with a breathingaperture in a socket on the fixed wall thereof, this socket beingadapted for connection to the breathing passages of the wearer via amouthpiece. Attached to the membrane is a tubular partition 7 screeningoff a fresh-air space 8 in the chamber from a used-air space 9. Thejunction of the partition to the membrane forms the seat 10 of anexhalation valve 11 comprising, for instance, a rubber disc attachedcentrally in the aperture of the tube 7 and the rims of which are freeto be pressed against the seat 10 in the closed position of the valve.The tube 7 extends freely into the socket '5 and its external diameteris smaller at this point than the inner diameter of the socket.

The membrane 6 is shaped, for instance by means of corrugations or inany other manner, so as to defin'e between an outer, extended positionand an inner, extended position (shown by dash lines 12, 14) a volume Vequal to the volume of the breathing passages leading from the chamberto the wearer and in the connection between the 3,096,778 Patented July9,, 1963:

ICC

latter and the chamber. The length of the tube 7 is chosen so as to letthe tube extend into the socket 5 even in the extended position of themembrane. The tubular partition forms a passage through the membranechamber for used-up exhaled air andleading from the breathing apertureof the socket 5 to the exhalation valve.

In principle, the operation of the device shown in FIG. 1 is as follows:

In inhalation, as the membrane 6 has reached its inner extended position14, the inlet valve 2 is opened'owing to the influence of the membrane,which then actuates the lever 4 in the opening direction of the Valve 2,thereby admitting fresh air to the membrane chamber. In the dead spacein the breathing passages of the wearer and in the connections betweenthese and the chamber there is likewise fresh air of volume V. This airforms the first portion of the exhalation and flows through the slotbetween the tubes Sand 7 into the chamber 1 as the membrane passes fromits inner to its outer position. The valve 11 then opens and during therest of the exhalation the bad air from the lungs flows through thetubes 5 and 7 and through the said valve into the surrounding medium. Atthe subsequent inhalation, the wearer first inhales the volume V offresh air from the space 8 as the membrane 6 passes from its outer toits inner position. The wearer then obtains the remaining quantity offresh air for the inhalation from the valve 2. For each inhalation,there is thus a saving amounting to an air quantity of volume V.

In the embodiment shown in FIG. 2, the screening partition is formed bya flexible tube 15 which is extendable, being provided with.corrugations, and is connected at one end to the membrane surroundingthe outlet valve 11 and at its other end. to the breathing aperture, iethe socket 5. The valve 11 is mounted on a spider 17' located in themembrane aperture. Owing to the corrugations or elasticity of the tubeor to both these factors, the tube permits the membrane to flex to aninner and to an outer extended position, just as was described in connection with the foregoing embodiment. The tube is provided with aperturesin the form of sickle-shaped slits forming movable flaps 16 allowingpassage of gas in .both directions.

The volume V of fresh air from the dead space of the wearer and of thedevice flows during the exhalation into the space 8 of the chamber viathe apertures at the flaps 16, since the pressure in the tube 15 duringthe exhalation is higher than in the space 8.

When the membrane 6 reaches its outermost position, the pressure in thechamber 1 and in the tube 15 is the same and the flaps return to theirneutral positions, whereupon the tube 15 forms a closed-off spaceleading the rest of the exhalation to the valve 11 to the surroundingmedium. In inhalation, a lower pressure is created in the tube 15 thanin the chamber 1 and the flaps open towards the tube interior allowingfresh air from the chamber to pass through. The invention is not limitedto the embodiments shown, these serving only as examples illustratingthe principle of the invention. It is however possible to place theexhalation valve on some other Wall of the chamber than the membrane.This removes the need for a movable tube but the increased dilference indepth between the exhalation valve and the membrane necessitates ahigher opening pressure on the exhalation valve.

Inhalation may be considered as divided into three stages. During thefirst stage, while both valves are closed, the diaphragm moves from theouter extended position to the inner position so that the areacorresponding to the volume V is sucked into the lungs of the wearer.Next, the inlet valve is opened when the diaphragm reaches its innermostextended position, and additional fresh air is applied as the wearerinhales. The last stage of inhalation is that when fresh air from theinlet valve fills the passages leading from the chamber to the lungs.Since this air does not ever reach the lungs its oxygen cannot be used,and this air has a high oxygen content.

Exhalation may be considered divided into two stages. During the firststage the air in the breathing passages from the chamber to the lungs ofthe wearer flows into the chamber and causes the diaphragm to move fromits inner extended position to its outer extended position. During thisstage of exhalation the outlet valve is closed. Accordingly, the airfrom the breathing passages flows into the space 8 of the chamber. Whenthe diaphragm has reached its outermost extended position, the secondstage begins. At this point the outlet valve 11 opens and the air fromthe lungs of the wearer, which is of low oxygen content, escapes throughthe outlet valve. When exhalation is finished, the outlet valve closes,and the first inhalation stage begins.

The purpose of the device is to conserve the supply of air by preventingmixing between the used air and the unused air, that is, between airwith low oxygen content and that with high oxygen content. Thearrangement is such that the air from the lungs of the wearer escapesthrough the tube 7 and the outlet valve, while the chamber 8 containsonly air having a high oxygen content. Accordingly, the tube 7 or someequivalent partition serves the purpose of preventing the fresh air inchamber 8 from escaping through the outlet valve during the second stageof exhalation.

What is claimed is:

1. A breathable gas regulating device comprising a housing having avalve chamber therein, an extensible diaphragm forming one wall of saidchamber, an outlet valve mounted on said diaphragm, an inlet valvelocated in a wall of said housing opposite said extensible diaphragm,actuating means operatively connecting said diaphragm and said inletvalve, a source of breathable gas connected to said inlet valve, asingle aperture in said wall of said housing opposite said diaphragm fordirectly conducting said gas to and from a point of use, a conductingtube extending through said chamber, one end of said tube beingconnected to said diaphragm and disposed around said outlet valve andthe other end of said tube extending through said aperture at all timesand said tube having a smaller diameter than said aperture to allow freeflow of gas between said chamber, said tube and said outlet.

2. A breathable gas regulating device comprising a housing having avalve chamber therein, an extensible diaphragm forming one wall of saidchamber, an outlet valve mounted on said diaphragm, an inlet valvelocated in a wall of said housing opposite said extensible diaphragm,actuating means operatively connecting said diaphragm and said inletvalve, a source of breathable gas connected to said inlet valve, asingle aperture in said wall of said housing opposite said diaphragm fordirectly conducting said gas to and from a point of use, an extensibleconducting tube in said chamber, one end of said tube being connected tosaid diaphragm and disposed around said outlet valve and the other endof said tube being connected to said wall of said housing opposite saiddiaphragm and around said single aperture to place said tube in directcommunication with said aperture, said tube having means communicatingflow between said chamber and said tube.

References Cited in the file of this patent UNITED STATES PATENTS2,383,649 Heidbrink Aug. 28, 1945 2,695,609 Nourse et al Nov. 30, 19542,788,001 Brown Apr. 9, 1957 2,823,739 Kimes Apr. 1, 1958 2,871,854Lambertson Feb. 3, 1959 FOREIGN PATENTS 1,038,345 France May 6, 1953

1. A BREATHABLE GAS REGULATING DEVICE COMPRISING A HOUSING HAVING AVALVE CHAMBER THEREIN, AN EXTENSIBLE DIAPHRAGM FORMING ONE WALL OF SAIDCHAMBER, AN OUTLET VALVE MOUNTED ON SAID DIAPHRAGM, AND INLET VALVELOCATED IN A WALL OF SAID HOUSING OPPOSITE SAID EXTENSIBLE DIAPHRAGM,ACTUATING MEANS OPERATIVELY CONNECTING SAID DIAPHRAGM AND SAID INLETVALVE, A SOURCE OF BREATHABLE GAS CONNECTED TO SAID INLET VALVE, ASINGLE APERTURE IN SAID WALL OF SAID HOUSING OPPOSITE SAID DIAPHRAGM FORDIRECTLY CONDUCTING SAID GAS TO AND FROM A PONT OF USE, A CONDUCTINGTUBE EXTENDING THROUGH SAID CHAMBER, ONE END OF SAID TUBE BEINGCONNECTED TO SAID DIAPHRAGM AND DISPOSED AROUND SAID OUTLET VALVE ANDTHE OTHER END OF SAID TUBE EXTENDING THROUGH SAID APERTURE AT ALL TIMESAND SAID TUBE HAVING A SMALLER DIAMETER THAN SAID APERTURE TO ALLOW FREEFLOW OF GAS BETWEEN SAID CHAMBER, SAID TUBE AND SAID OUTLET.